Season 5 will feature one final battle between humanity and alien race Esphenis, which will determine the fate of the earth.

In the season 4 finale, the 2nd Mass did destroy the Espheni's power core, but Tom is seemingly lost in space in an Espheni ship and is now caught in some kind of waking dream. His last words in the finale were: "You're beautiful."

According to a new TV Line report, Tom's alien encounter in space will make things difficult for the 2nd Mass leader when he returns.

"This [mysterious alien] promptly suggests a rallying cry to Tom, one that will rub some of his comrades in the 2nd Mass the wrong way after he (somehow!) gets back to Earth."

Tom exposed himself to an unknown alien in the season 4 finale. The last time this happened, the former professor ended up being the first victim of the Espheni's eye worms. Considering Tom will mysteriously find his way back from space in the premiere episode, it is no surprise that some of his troop members will be reluctant to trust their leader.

Series lead Noah Wyle also dished on the ending of Falling Skies and teased that not everyone will make it out alive in the finale.

Wyle told Tvline: "We tried to answer all the questions, to unravel all the mythology, and make it as satisfying an ending for the audience as it was for [the cast] to get our own sense of closure."

According to him Wyle season 5 will feature "10 of the strongest episodes we've ever done." So "in the final analysis, we finished strong, and I'm proud of it."

But for the stalwart fighters of the 2nd Mass, "We thin the herd along the way," Wyle said hinting of the casualties to come. "Not everybody makes it to the finish line," he added.

Here are the titles and synopsis of each of the season 5 episodes:

Episode 1 is titled Find Your Warrier: "Tom's life hangs in the balance as his beamer drifts into space; Tom encounters a surprising guest."